多场耦合作用下矸石-粉煤灰胶结充填体热-流-力-化响应行为

Whether coal mine backfill can effectively control subsidence without contaminating underground environment or not significantly depends on the mechanical stability and permeability of the backfill. Under the coupled effect of temperature field (temperature of the backfill and the environmental temperature), seepage field (fluid flow within the pore structures of the backfill), stress field (the backfill suffer from the roof pressure) and chemical field (the hydration of flyash and cement), the backfill will make varied responses, and perform different mechanical stability and permeability. By taking gangue-flyash cemented backfill as research object, this project will reveal the coupled thermal (temperature)-hydraulic (seepage)-mechanical (stress)-chemical (chemical reaction) mechanism of the backfill. Based on this mechanism, the coupled mathematical model will be developed. By taking advantage of the test equipment that will be made in this project, evolutions of the backfill’s temperature, water seepage, pore water pressure and strain will be investigated. Besides, the availability of the developed model will be validated. By means of numerical simulation, the thermal-hydraulic-mechanical-chemical response behavior of the backfill under the effects of different material proportions, backfill’s initial temperatures, environmental temperatures, backfill’s sizes and applied loadings will be illustrated. The research of this project is of certain theoretical and practical significance to preparing economical, environmentally friendly, stable and durable gangue-flyash cemented backfill.

煤矿充填能否有效控制地表沉陷且不造成井下污染，关键取决于充填体的力学稳定性和渗透性。在温度场（充填体自身及环境温度）、渗流场（充填体孔隙结构中的流体流动）、应力场（充填体承受顶板压力）和化学场（粉煤灰和水泥的水化反应）的共同作用下，充填体将作出不同响应，表现出不同的力学稳定性和渗透性。本课题以矸石-粉煤灰胶结充填体为研究对象，通过分析上述各场之间的相互作用关系，揭示充填体热（温度）-流（渗流）-力（应力）-化（化学反应）耦合作用机理，并在此基础上建立相应的耦合数学模型；利用所制作的试验装置来探究充填体的温度、渗水量、孔隙水压力、应变量的变化规律，并验证上述耦合数学模型的有效性；通过数值模拟研究在不同的材料配比、充填体初始温度、环境温度、充填体尺寸、外加载荷等条件下，充填体的热-流-力-化响应行为。本课题的研究对于制备经济、环保、稳固及耐用的矸石-粉煤灰胶结充填体具有一定的理论和实际意义。

充填采矿法通过将矿山固体废弃物填充入地下采空区的方式，能够有效地解决安全开采、地表沉陷、土地占用以及环境污染等问题。因此充填采矿法得到了越来越广泛的应用。本课题以矸石-粉煤灰胶结充填体为研究对象，通过分析影响充填体行为的温度场、渗流场、应力场和化学场之间的相互作用关系，揭示了充填体热-流-力-化耦合作用机理，并在此基础上建立相应的耦合数学模型；利用所制作的试验装置探究了充填体的温度、渗水量、孔隙水压力、侧压力等参量的变化规律，通过对比试验数据和模拟结果验证了模型的正确性和有效性。利用经过验证的模型预测了不同热、流、力、化边界条件下充填体的反馈行为。本课题的研究对于制备安全稳固、经久耐用及绿色环保的矸石-粉煤灰胶结充填体具有一定的指导意义。